That's strange, it should be there (make sure you're not looking in the railcraft/client/textures as that's not used for 1.2.5). Maybe try redownloading it, esp if you last downloaded it from the google drive, as sometimes certain files didn't get downloaded when they should have for some reason.

Covert changed the layout of the sprite sheets in the MC 1.4.x versions, so textures made for them won't work. Fortunately I figured this may cause issues when I textured that, so the fix for this particular problem is easy, just go to the railcraft/textures folder, and delete the "gui_coke_oven.png". Now rename "gui_coke_oven_NEWVERSION.png" to "gui_coke_oven.png", and everything should be peachy :)

Just to confirm, there does indeed seem to be an issue where for some reason the terrain.png file sometimes doesn't get downloaded from the Google Drive, and to be honest, I'm not sure why, as it doesn't appear to affect any other files.

Just to remind everyone that the Dropbox version, whilst eaiser to download, will most likely be to some extent, outdated, and thus it's recommended that one downloads the Google Drive version as all updated textures are saved straight to that.

I did replace the RP gem textures last week, although I'm not 100% happy with them, they should hopefully stand out less
Also, the block showing up weird when held is an Optifine bug, there is a patch to fix it, which I believe should be in the Optifine MC Forum thread.

I haven't worked much on CC, Laz worked on those, but I think the problem may reside to the version of CC you use. The one in Tekkit (1.3) is outdated and a lot of things have changed in later versions.
The Creeper heads are new in MC 1.4 :)

Just thought I'd let everyone know I've been working on some of the new Railcraft 6.6 stuff:
Some cool new power generation stuff has been added, although it's only for MC 1.3/1.4 so not compatable with Tekkit (the RC texture path has changed so it won't affect any of the 1.2.5 textures).

Shame as it would have been nice to credit them, or even see if any more textures were made.
Will credit John Lemon
Reminds me of this thread over at the MC Forums I found a few weeks back, doesn't seem to contain much though and it doesn't appear much progress was made, but it does contain these textures.

Right I have added most of those textures to the IC2 item sprite sheet, expect for the ones that already had JSTR textures. They look amazing I have to say, I was wondering if you know who made them by any chance?